Ключевые слова: above, counting, dam, deep, depth, distance, drought, environment, europe, exterior, flensburg, flood, gauge, germany, global, harbor, high, instrument, lake, level, lines, low, management, marker, measure, measurement, measuring, meter, nature, netherlands, number, outdoors, outside, pole, post, reservoir, rising, river, ruler, scale, sea, shortage, surface, tall, tide, warming, water,